The gut microbiome is composed of several species of bacteria, fungi, viruses, and other single-celled microbes. All human beings harbor about 10 trillion to 100 trillion microbial cells that live in and on the body. Most microbes have a symbiotic relationship with the host, while some are pathogenic that promote disease. The gut flora has a vital role in a healthy immune system, proper digestion, production of essential nutrients, and protection against harmful pathogens. Gut microbes majorly impact your behavior patterns, cognitive functions, and stress levels.
Each individual has a unique microbiome that is determined by various factors, such as genetics, environment, and medications. Gut health foods and diet are one of the key controllable factors that influence the composition of your gut microbiome. The food you consume nourishes the good and healthy gut bacteria and helps them grow, and the right diet can help maintain a healthy and diverse gut microbiome.
Dietary fiber provides the fuel to the good bacteria in your body. Fermented foods can introduce good bacteria (probiotics) to your gut. The way food is prepared is also important. Fresh foods that are minimally processed and nutrient-dense are beneficial for your gut health.
Gut Inflammation and its Causes
Inflammation occurs when your immune system is triggered by an offending agent. The immune system releases inflammatory chemicals to fight off the threatening invader as a biological response. While a bit of inflammation helps in healing, chronic inflammation can trigger body pain and diseases.
There are two types of inflammations:
- Acute inflammation– It is the response to a sudden injury, such as cuts and scrapes. The body sends inflammatory cells to start the healing process.
- Chronic inflammation– The body keeps sending inflammatory cells even in the absence of any danger. For instance, in rheumatoid arthritis, the inflammatory cells target joint tissues and cause severe pain and damage to the joints.
The most common causes of chronic inflammation are:
- Exposure to industrial chemicals or pollutants.
- Autoimmune diseases, such as lupus, in which the immune system malfunctions and attacks healthy tissue.
- Untreated acute inflammation, typically caused by an infection or an injury.
Many lifestyle factors can cause inflammation. These include:
- Drinking too much alcohol and smoking
- Too much exercise
- Chronic stress
- Consuming too many inflammatory foods, such as processed meat, refined sugar, simple carbohydrates, and trans fats.
- Certain health conditions and medications
You can follow an anti-inflammatory diet to treat inflammation. Some of the best anti-inflammatory foods are:
- Green leafy vegetables
- Olive oil
- Fatty fish
- Nuts and seeds
- Fruits such as oranges, blueberries, strawberries, and cherries
- Spices such as turmeric and black pepper.
Plants have their own defense mechanism that protects them from insects, bacteria, fungi, and viral infections. They produce certain chemicals called phytonutrients, which are a part of their immune system. When we consume these plant-based products, we essentially take up these phytonutrients. Research has shown that phytonutrients protect us against inflammation, heart disease, and cancer. To get all these nutrients in our system, try to eat a variety of different colors of fruits and vegetables. Certain fruits and vegetables such as apples, potatoes, pears, and zucchini, have most of their colors in the skin and that’s where most of the phytonutrients are. Therefore, you should avoid peeling certain plants and vegetables, whenever you can.
How do cooking methods affect inflammation?
An anti-inflammatory diet is not just about choosing the right foods, but also the way you cook them. Frying, grilling, or roasting foods at high temperatures increases the inflammation-causing agents called advanced glycation end products (AGEs). AGEs are a critical part of the metabolic process and aren’t innately harmful, but a high concentration of AGEs can be dangerous. High levels of AGEs in the blood can increase chronic inflammation and oxidative stress in the body. They are also known to accelerate aging. AGEs are not only produced at high cooking levels, but they are also naturally present in animal products, such as red meat, beef, and pork. When foods that already contain AGEs are cooked at high temperatures, they form new AGEs. This results in problematic quantities of AGEs in the bloodstream. The best way to cut down AGEs is to limit these foods in your diet and incorporate more raw fruits and vegetables.
Cooking methods such as steaming, baking, and stir-frying are some of the best ways to avoid inflammation-promoting properties and retain its nutrients.
Role of dietary fiber in optimizing Gut health
High fiber foods are the best fuel for healthy bacteria in the gut. It relieves constipation and helps to regulate cholesterol and blood sugar levels. Fiber can be divided into two categories:
- Soluble fiber and
- Insoluble fiber.
Soluble fiber can be dissolved in water and turns into a gel during digestion. Sources of soluble fiber include oat bran, lentils, and fruits such as mangoes and grapefruit.
Insoluble fiber particularly helps to ease your bowel movements. Its sources include vegetables, wheat bran, and whole grains.
Here are some ways to add more fiber to your diet.
- Choose minimally processed whole grains, fruits, and vegetables over processed carbohydrates.
- Snack on homemade popcorn.
- Add nuts and seeds to your recipes.
- Include more legumes in your diet.
Try adding both soluble and insoluble fiber to your diet and increase your fiber intake gradually. The recommended intake of dietary fiber for women is 25 grams a day, while that for men is 30 grams a day.
Prebiotics for Gut Health
Prebiotics are a type of non-digestible dietary fiber that provides nourishment to the good bacteria in your gut. The modern-day processed and high-fat diets are starving your gut microbes, turning the diverse gut ecosystem into a microbe monoculture. As a result, the gut becomes devoid of energy and breaks the linkages between the intestinal cells, which leads to a leaky gut. This means that nasty toxins can seep into the gut barrier and cause inflammation in the body and promotes diseases over time.
Prebiotics increase carbohydrate metabolism and improve the uptake and bioavailability of minerals. They also help prevent colon cancer and reduce some of the risks of cardiovascular diseases. Prebiotics are abundant in legumes, beans, flax seeds, garlic, and berries. You can boost your prebiotics intake by:
- Adding legumes to your soups and salads
- Snacking on fresh fruits
- Eating high-fiber and unprocessed breakfast cereals with nuts and seeds
- Avoiding refined foods.
However, prebiotics is not suitable for everyone. People with FODMAP intolerance, irritable bowel syndrome (IBS), or small intestinal bacterial overgrowth (SIBO) should ideally avoid prebiotics as they can worsen the symptoms.
Probiotic-rich foods and their role in Gut Health
Probiotics are live bacteria (and sometimes yeast) that are beneficial for your health. Fermented foods are rich in indole-3-lactic acid (ILA) which is converted into indole-3-pyruvic-acid (IPA) by your gut bacteria. IPA is one of the most important antioxidants in the body. Although yogurt is known as one of the best probiotic sources, many other foods are equally (or more) potent sources of probiotics.
Some of the best sources of probiotics are:
Kefir: It is a fermented drink prepared by adding kefir grains to milk (fermented milk). It has three times more probiotics than yogurt and is also suitable for lactose-intolerant people as the sugar in milk (lactose) is almost completely used up by the bacteria.
Fermented Pickles: Pickles are prepared either with vinegar or fermented with brine. While both are equally appetizing, fermented pickles hold much more beneficial bacteria than the ones prepared with vinegar.
Kombucha: It is a fermented drink made with sweetened black or green tea. Kombucha is a great probiotic source that can help strengthen your immune system and boost digestion. Tea contains several polyphenols and antioxidant compounds that fight free radicals in the body.
Kimchi: It is fermented vegetables such as cabbage and radish seasoned with salt, red chili, garlic, and more. Kimchi is a probiotic powerhouse packed with nutrients and is good for your digestive tract. It is known to reduce inflammation, support heart health and improve digestion, among many other health benefits.
Traditional buttermilk: Traditional buttermilk is the by-product of the butter-making process. The liquid remaining after churning out butter from milk is fermented by the bacteria present in the air. However, the modern buttermilk is prepared by adding bacteria to skim milk, which ferments it. Buttermilk contains almost the same amount of calcium as milk, only with less fat. Make sure to pick buttermilk with an ‘’active cultures’’ label.
Yogurt: When selecting yogurt, opt for unpasteurized and yogurt without artificial sweeteners with the least amount of ingredients as they have the most beneficial probiotics. Here are some ways in which you can add more probiotics to your diet.
- Plain yogurt can be used to make dips and salad dressings.
- Fermented cabbage, cucumber, and radish can make great condiments.
- Try adding kefir to your smoothies.
- Swap your tea or coffee with Kombucha or buttermilk.
Studies have found that fresh fruits, vegetables, dark chocolate, tea, coffee, and red wine contain polyphenols, which are associated with increased microbial diversity. Additionally, oily fish, nuts, and seeds are great sources of omega-3 fatty acids that are known to diversify your gut microbiome and reduce inflammation. These are essential fats but our bodies can’t produce them on their own. Therefore, we must get them from our diets.
You may take your daily dose of probiotics in a single meal or space them throughout the day. While adding probiotics to your recipes, allow your dish to cool down, and add the probiotics right before serving as heat can kill its good bacteria. The recommended dose of probiotics for children is 5 to 10 billion CFUs per day, and that for adults is 10 to 20 billion CFUs per day.
Although probiotics are safe to take, there are certain circumstances when eating probiotic foods are not recommended. People with compromised immunity or a serious illness should avoid probiotics, as they can lead to bacterial or fungal infections.
What are Symbiotic foods?
Symbiotic foods are food items that have the characteristics of both prebiotics and probiotics that work synergistically to support gut health. They nourish the gut microbes and establish new, equally beneficial colonies of gut microbes. Symbiotics can help in better survival and implantation of the live microbes in the gut. This way, symbiotics can overcome the possible survival problems of probiotics. Symbiotics also selectively promote the growth of certain beneficial bacteria.
Symbiotic foods are thought to be beneficial in many ways:
- Inflammatory bowel disease (IBD): Symbiotic foods can reduce gut inflammation and relieve IBD symptoms.
- Lactose intolerance: Many people are lactose-intolerant and find it difficult to assimilate the sugar found in milk products (lactose). Studies have shown that symbiotics can reduce its symptoms.
- Immune function: Symbiotics help to optimize intestinal immunity and reduce the chances of infection due to probiotics.
- Traveler’s diarrhea: It is caused by consuming contaminated food and water when you travel to a place with different hygiene practices. Symbiotic foods may prevent diarrhea and cramps.
- Obesity and Hyperglycemia: Consuming symbiotic foods is associated with reduced inflammation and bad cholesterol levels. It also lowers the risk of type 2 diabetes, obesity, and insulin resistance.
Sources of symbiotic foods are:
Miso: It is a fermented paste made from soybean and other grains. It can be used to prepare the famous miso soup, ferment other vegetables or prepare delicious sauces.
Tempeh: It is made from fermented soybean or chickpeas. It is similar to tofu but it is more firm. High-quality tempeh has a velvety texture and a nutty, mushroom-like aroma. It has to be steamed before adding it to recipes. Tempeh also makes a great meat substitute.
Sauerkraut: It is thinly sliced cabbage that has been fermented by lactobacillus bacteria. Wash the cabbage thoroughly and cut it into really thin slices. Cover it with sea salt (15g salt per kilo cabbage). Knead the cabbage until it releases moisture and leave it for 4-5 hours. Cover the bowl with a cloth, making sure that the cabbage stays submerged in the water. Keep it in a cool, dark place and consume it after about 10 days.
The Benefits of Food Diversity on the Gut
Food diversity is the variety of foods in your diet. Your gut microbiota contains a wide range of bacterial species and different bacteria are responsible for digesting different foods. The food you consume can either help you boost your microbiome diversity or skew the ratios of the beneficial and gut-healthy bacteria. For example, consuming dietary fiber from plant-based sources, such as fruits, vegetables, and legumes, fuels the gut bacteria in your gut.
On the other hand, if you eat only high-fat, low-fiber, processed foods, the gut produces more of those bacteria that digest these foods. There will be less fuel for other bacteria, which will starve them until they die off. Thus, certain bacteria will out-compete other bacteria and result in a loss of microbial diversity. Your body constantly tries to heal your gut, but it often takes a lot of time and effort to reverse this. In fact, in some cases, it is nearly impossible to bring back the lost gut bacteria. In some cases, targeted supplementation can help you get certain nutrients and compounds that are required by your body.
Importance of portion control, meal timings, and water in your diet
We often tend to eat everything that is there on our plates. These days, restaurants often serve large portions, which encourages us to overeat. Portion size is the amount of food you eat in a single sitting, whereas serving size refers to the standard quantities of the food or drink mentioned on the Nutrition Facts Label of a product. Portion size can be more or less than the serving size. Controlling your portion is important as it allows you to eat only what your body needs.
If you don’t pay attention to portion size, the calories can add up quickly. Such practices can help you avoid the harmful effects of overeating and achieve your weight-loss goals faster. Here are some of the ways in which you can control your portion size.
- Read labels for suggested serving size.
- Use measuring cups or a weighing scale.
- Store portioned meals in single-serve containers.
- Increase your fiber intake by adding fresh fruits and vegetables to your diet.
- Eat your food without distractions to avoid overeating and take your time to eat.
Remember, you don’t need to finish everything there is on your plate. If you are full, the food you are eating is already a waste. In fact, overeating has many toxic effects on the body, apart from weight gain.
Meal timings are just as important as the food you eat. Eating at the right intervals regulates your body cycle, boosts metabolism, and helps your body detox. Ideally, you should have your breakfast within the first hour of waking up. This helps your body to energize and re-hydrate after fasting and being dehydrated overnight. Eating small and frequent meals helps in better utilization of calories and prevents them from being stored as fat.
Therefore, you must eat every 2-3 hours. There should be a gap of three hours between your dinner and bedtime. This allows your body to properly digest the food and prepare for bedtime.
Depending on a person’s age, gender, location, and BMI, an average adult is 60% water. Water helps to lubricate and cushion your joints, regulate body temperature, and nourish your brain and spinal cord. Maintaining water balance in the body is essential to prevent dehydration or overhydration, both of which can be detrimental to your overall health. Dehydration can result in low energy levels, mood, blood pressure, skin moisture, and cognitive impairment. Overhydration occurs when one drinks too much water in a short amount of time. This makes it difficult for the kidneys to function normally. Water intoxication results in fluid retention, headache, and vomiting. The amount of water you need depends largely on your weight and environment.
The recommended daily fluid intake is about 3.7 litres for men and about 2.7 litres for women. Fruits and vegetables like strawberries, broccoli, and cucumbers are 90% water and can supplement your water intake while providing essential nutrients and fiber.
How a healthy diet influences a healthier gut?
Gut bacteria produce enzymes that break down and ferment dietary fiber to produce short-chain fatty acids (SCFAs) and gases such as propionate, acetate, and butyrate.
- SCFAs strengthen the immune system, nourish the gut barrier and prevent inflammation. SCFAs also reduce the pH of your gut. A lower pH inhibits the growth of harmful bacteria in the gut.
- Butyrate is the main source of energy for the cells lining the colon and prevents a leaky gut. It also helps suppress inflammation in the gut.
- Propionate is known to lower serum cholesterol levels and stimulate satiety-inducing hormones.
- Acetate helps maintain a healthy gut environment and nourishes the good bacteria in the gut.
Thus, you should aim for an overall sustainable diet containing essential nutrients, enriched with high-fiber plant-based products and fermented foods. Limit your intake of processed, high-fat, sugary foods and alcohol.
An unhealthy gut can lead to problems like autoimmune conditions, fatigue, mood swings, skin irritation, and signs of irritable bowel syndrome (IBS) including bloating, diarrhea, constipation, and abdominal pain. Eating a balanced diet is one of the best ways to achieve microbial diversity. Fiber is a key nutrient for a healthy gut microbiome. A diet high in inflammatory foods such as refined sugars and processed foods decreases the number of good bacteria in the gut. Cooking methods such as frying, grilling or roasting at high temperatures produces toxins known as AGEs in the food which triggers inflammation in the body and accelerates aging.
Symbiotic foods combine the properties of prebiotics and probiotics that have a synergistic effect on gut health. Symbiotic foods can overcome the survival difficulties of probiotics. Alongside, portion control is a valuable tool when you are trying to lose or maintain your weight. In addition, it is important to stay hydrated throughout the day as it ensures your digestive system is running smoothly and enables the fiber to do its job. Also, eating at the right intervals boosts your metabolism and improves digestion.
Tim Koping (Medical M.Sc Physiology, Founder of Original Eating, and a Professor at a Leading Health Institute in the US): I am a medical M.Sc physiology graduate and the founder of Original Eating, an online resource that provides information and advice about healthy eating. I have a strong interest in health and nutrition, and I am passionate about helping people to eat well and live healthily. I have over 15 years of experience working in the health and nutrition industry, and I am dedicated to providing accurate, reliable information that can help people to make healthy choices for themselves. My work with Original Eating has been featured in publications such as Men’s Health and more, and I am frequently consulted by journalists for expert commentary on dietary issues. However, in my spare time, I also enjoy reading, hiking, and playing the guitar.